Core D: Morphology Core The purpose of the Morphology Core is to provide state-of-the-art, standard and specialized morphology and histology services to the various projects of this Program Project Grant effort. The Morphology Core Director (David Gordon), and Co-director (Jonathan Homeister) will continually meet with the various investigators of our projects to discuss experimental design and to mutually formulate the gross, microscopic and histologic studies to be performed. Standard procedures shall include assistance with tissue harvesting and fixation, further tissue processing/embedding, generating routine histologic sections (paraffin embedded or frozen sections), immunocytochemistry and in situ mRNA hybridization. Specialized procedures shall include performing gross autopsies on selected new genetically engineered mice to look for: congenital anomalies, evidence of thrombosis or hemorrhage, and other pathology, which may be characteristic of the specific genetic alteration. We will also assist individual projects in working out the conditions for using specific new immunostaining or in situ hybridization methods (e.g. for newly acquired antibodies or probes), with the appropriate controls, and with other new morphology techniques as the need arises (e.g. laser Capture Microdissection). Finally this Morphology Core will assist investigators in documenting the findings via routine photomicroscopy and selected morphometry.